Summary of Significant Accounting Policies (Detail Textuals 2) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Accounting Policies [Abstract]
Unearned interest, dealer discounts and allowance for credit losses	$ 186.3	$ 169.1
Average dealer discount associated with new volume	7.51%	8.08%	8.44%
Cash paid for income taxes	$ 8.5	$ 7.3	$ 10.8
Cash paid for interest, including debt origination costs	$ 8.8	$ 6.1	$ 5.7